Since I've owned my Lumina I've had vibration problems. I've managed to isolate and fix the causes one by one, but I'm stuck on this last puzzle!
I rebuilt the rear drum brakes on my Lumina a few months back (new pads, drums, cylinder, etc...) in an attempt to cure a vibration that was emanating from the rear end when I applied the brakes and decelerated the car. This vibration occurs from any speed over 50MPH when the brakes are applied. The vibration dissipates once you hit the 40MPH mark and the brake pedal feels normal. I know that the rear wheels are causing this as I've confirmed with the parking brake at high speeds.
I'm thinking that the bearings might just be worn out as they've got 226,000 miles on them. I've read a few places that worn/pitted bearings can cause vibrations at certain speeds & when a certain amount of force is applied in a general direction on the bearing due to wear.
Anyone have ideas/care to confirm my suspicions?